Free written scope consultation - allowances, timeline, and change-order rules on paper before a single trade is scheduled
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AfterFast, Reliable Home Additions & ADU Across Keene
A home addition in Keene, TX typically runs $45,000 to $130,000 depending on square footage, foundation type, and whether you’re building up or out. ADU construction, including detached units and garage conversions, lands between $90,000 and $220,000 for a complete permitted build. Barrett & Sons Construction handles every step in Keene from the first sketch through final inspection, with written change orders before any scope shift and permits pulled on every eligible job. Call (877) 610-1318 to schedule your free estimate.
Keene isn’t just another stop on a route sheet for us. We know this city’s rhythm, and we’ll say it plainly: most of our Keene customers don’t do business Friday sundown to Saturday sundown, and neither do our crews when they’re working here. That’s not a policy manual talking. That’s what happens when you spend time in a town anchored by Southwestern Adventist University and you listen to the people who live there. It matters for scheduling, for neighbor relations, and for getting the job done without friction.
Why Barrett & Sons Construction Is Keene’s Preferred Home Additions & ADU Company
Tom Barrett started this company in 1998 and put his name on the truck. His sons run crews. That’s the whole ownership chart. When you call about an addition or ADU in Keene, you get a live person, not a call center routing matrix. We coordinate scheduling and dispatch from our Dallas-Fort Worth office, and crews serve Keene locally.
The soil under Keene is Blackland Prairie clay heavy montmorillonite, to be exact. It heaves several inches in wet winters and shrinks and cracks through dry summers. That means any addition we design here starts with a serious look at foundation conditions, drainage grading, and slab performance. An out-of-town outfit might pour a slab that looks fine in March and shifts by August. We’ve seen it. We plan against it.
We also understand the Sabbath reality in Keene. A meaningful share of this town observes Friday sundown through Saturday sundown and won’t permit job-site work during that window. Out-of-town contractors show up Saturday morning and lose the job permanently. We book consultations, concrete pours, and crews Sunday through Friday. We’ll put that in writing if you want it there. That single habit has earned us repeat work and neighbor referrals that no advertising budget can buy in Keene.
Our Home Additions & ADU Services in Keene
Here’s what we handle for Keene homeowners, with the local context that actually changes the work.
ADU Design & Permitting
Before we talk square footage, we talk about what Keene and Johnson County will approve. Zoning for accessory dwelling units has specific setback, height, and lot-coverage limits depending on whether your property sits in the older mid-century section near the university or in the newer tract developments built since the late 1990s. We handle the full design package and pull every permit ourselves. The permit inspector works for you, not for me. That’s why I like him on the job.
Garage Conversion ADU
Converting an attached garage into a dwelling in Keene typically costs $30,000 to $80,000. Older Keene homes with aging slab foundations need careful assessment before we frame walls, because a slab that’s fine for parking cars isn’t necessarily ready for plumbing, insulation, and a full living load. We’ve converted garages across Keene, and the ones on the original mid-century slabs almost always need some drainage and grading work first.
New Detached ADU
A new detached ADU in Keene runs $90,000 to $220,000. This is a full construction project: foundation, framing, electrical, plumbing, HVAC, and a roof that can stand up to the ice storms and high-wind thunderstorm bursts this part of North Texas sees in seasonal spikes. We run GAF roofing systems on our detached builds because Keene weather doesn’t give second chances. If you want a separate unit for family, rental income, or a quiet workspace, we’ll walk you through the real cost before anything starts.
Junior ADU & Interior Conversion
Not every addition requires pouring new concrete. A junior ADU or interior conversion works inside the existing footprint of the house, which makes it one of the most cost-effective ways to add a second living space in Keene without triggering the full cost and timeline of a detached build. These projects often tie into our Kitchen Remodeling in Keene work, since a junior ADU usually needs its own kitchenette and a remodeled bathroom to feel like a true separate unit. If you’re already planning a Bathroom Remodeling in Keene, we can combine scopes and reduce the disruption.
What happens when you call
- 1
A real person answersNo phone trees - you reach a local pro.
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You get an upfront price rangeHonest numbers before anyone is dispatched.
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A background-checked tech heads outLicensed & insured, dispatched right away.
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You approve before work beginsNothing starts until you say go.
Trusted Brands We Service in Keene
We install materials you can look up, not mystery brands off a van. In Keene, that means GAF for roofing systems on our additions and ADU builds, and Schluter in bathroom and wet-area applications where moisture resistance is non-negotiable. If you have a preference for Sterling fixtures or Grohe plumbing, we’ll spec them and price them in writing. Keene homeowners deserve the same premium-brand depth we bring to every job across Johnson County. The difference is we keep it local: same crews, same accountability, same 90-Day Done Right Promise written on the contract.
Common Home Additions & ADU Problems We See in Keene Homes
- Foundation movement from Blackland Prairie clay. Keene sits on expansive clay that heaves in wet winters and cracks in dry summers. Any addition built without a proper foundation assessment will show cracks at the seam where new meets old within a year or two.
- Drainage failures on flat lots. Many Keene lots near the university have minimal natural slope. Water pools at the foundation line, and we regularly find that the “simple addition” the homeowner imagined actually needs regrading and a French drain before the first wall goes up.
- Sabbath scheduling complications. This one’s unique to Keene. Contractors who don’t know the community will schedule a Saturday pour and then wonder why the homeowner won’t answer the door. We book Sunday through Friday and build the schedule around the reality of the town.
- Disconnected additions on aging infrastructure. The mid-century homes clustered near Southwestern Adventist University often have electrical panels and plumbing lines that weren’t sized for an extra living unit. We scope that work early, in writing, so there’s no surprise invoice at the end.
Pricing for Home Additions & ADU in Keene, TX
| Project Type | Keene Price Range |
|---|---|
| Room Addition | $45,000 - $130,000 |
| Detached ADU (permitted new build) | $90,000 - $220,000 |
| Garage Conversion ADU | $30,000 - $80,000 |
| Junior ADU / Interior Conversion | Often runs 40-60% of a detached ADU build, quoted per scope |
| Sunroom or Enclosed Patio | $25,000 - $60,000 typical range, dependant on foundation, glazing, and HVAC integration |
What moves the price in Keene most, beyond square footage, is your lot’s drainage profile and the condition of the existing foundation on older homes near the university. A second-story addition on a mid-century pier-and-beam home costs differently than the same square footage on a newer engineered slab. Every scope, every allowance, every price change arrives as a written change order before work happens. No surprise invoices at the end. The allowance that isn’t on paper is a surprise waiting for a date.
Call (877) 610-1318 for a free, written estimate on your Keene addition or ADU. We’ll give you real numbers, not a range that floats.
We Also Serve Cities Near Keene
Our Home Additions & ADU team works throughout Johnson County and the southern DFW corridor. Beyond Keene, you’ll find us on job sites in Cleburne, Joshua, Burleson, and Crowley. Same crews, same written change orders, same permits pulled. If you’re in a neighboring town and want the full picture, see Home Additions & ADU in Keene for what our local customers experience, then call us for your own estimate.
Serving Keene, TX - Our Local Coverage Area
We’re based in the Keene area and know this community well. Use the map below to see our service coverage - if you’re nearby, we can almost certainly help.
FAQs - Home Additions & ADU in Keene
How quickly can Barrett & Sons respond to Keene?
We respond to Keene inquiries same day, and because we coordinate from our Dallas-Fort Worth office with crews serving Keene locally, we can typically get a consultation on your calendar the same week you call. We don’t rush the build, but we don’t make you wait three weeks for a conversation. Call (877) 610-1318 and you’ll talk to a live person.
Do you serve all Keene neighborhoods?
Yes. We cover all of Keene’s 76059 zip code, from the older mid-century streets near Southwestern Adventist University to the newer tract developments built since the late 1990s on the south and east sides of town. If your house is in Keene, we’re there.
Do you offer emergency service in Keene?
For roof leaks, storm damage, or a structural issue that can’t wait, we prioritize Keene calls and work Sunday through Friday to respect the community’s Sabbath observance. A live person answers 24/7, so if something’s urgent, call (877) 610-1318 and we’ll get you scheduled for the earliest available day.
How does Keene pricing compare to nearby cities?
Keene pricing runs in the same range as Cleburne and Joshua, and typically 5-10% below what you’d see quoted in Burleson or Crowley for the same square footage. The bigger variable in Keene isn’t the city. It’s your lot’s drainage profile and the age of your foundation. We’ll walk the property, test the soil if the foundation looks questionable, and give you a written range that holds.
What warranty do you offer in Keene?
Every job carries our 90-Day Done Right Promise, written on the contract. If it’s not done right, Tom Barrett comes back and makes it right with one phone call. We also stand behind the manufacturer warranties on every brand we install, from GAF roofing to Schluter waterproofing. When we say we’ll fix it, we mean we’ll be back in Keene to fix it. Call (877) 610-1318 for an exact quote. Estimates are free.
Will the price change once work starts in Keene?
No, not without your signature. Every price change, every allowance adjustment, every scope modification arrives as a written change order before the work happens. We don’t hand you a different bill at the end. That’s the whole reason we publish our pricing and put it in writing. If a Keene job needs something we didn’t see, you’ll know the cost before we touch it, and you’ll approve it in writing first.
Written by Tom Barrett, Owner at Barrett & Sons Construction, serving Keene since 1998.